This invention relates to track assemblies for use with crawler-type vehicles.
As is well known, track roller assemblies are typically used with crawler-type vehicles and are mounted on track frames intermediate the track sprocket and idler for maintaining the lower run of the track in firm engagement with the underlying terrain. Because crawler-type vehicles are used in extremely hostile environments, it is necessary that the track roller assembly be provided with adequate lubrication or else, due to the immense loads frequently imposed thereon, the track roller assemblies will fail after a very short period of use.
The track assemblies also typically include track pins, that is, shafts, which pivotally interconnect adjacent track links. The interface of each track pin and associated bushing must also be adequately lubricated to prevent failure since they too are heavily loaded and may fail rapidly if abrasive material typically present in the operating environment enters the joint.
Servicing of such components in the field is quite cumbersome and, due to the high cost of crawler-type vehicles, the extensive downtime associated with servicing is to be avoided.
As a consequence, during fabrication of crawler-type vehicles, considerable effort is made to inspect the track assemblies to ensure that they have been provided with lubricant. Notwithstanding the inspection techniques that have evolved to date, occasionally a vehicle will leave the place of manufacture with one or more of its track roller assemblies or track pins free of lubricant. Failure due to lack of lubrication can be anticipated shortly thereafter. Thus, there remains the need for a foolproof means of inspecting track roller assemblies or track pins to ensure that they are provided with lubricant at the time the vehicle employing the same is first readied for use after manufacture.
Moreover, replenishment of lubricant in the track roller assembly or in track pins is from time to time required. In the typical assembly, it is necessary to remove a plug from a bore in the shaft of the assembly to determine whether there is lubricant present and, if not, to add lubricant. Where the lubricant supply is adequate, removal of the plug and subsequent replacement is, in a sense, a wasted effort since no servicing is required. Thus, the time spent in the removal and replacement of plugs without the addition of lubricant is an expense to the owner of the vehicle, albeit a necessary one, to ensure that failure due to lack of lubricant will not take place. Clearly, it would be advantageous to eliminate or minimize such expense and yet be able to ensure that adequate lubricant is present to prevent failure.